Example 1: center div horizontally and vertically

.parent {
  position: relative;
}
.child {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

Example 2: how to center a div vertically and horizontally

.container{	
	margin: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
  	width: /* Define the width here; */
    height: /* Define the height here; */
}

/*You have to define the width and height! */

Example 3: how to center horizontally and vertically block div

#html code

	
CSS is cool


#css code
.parent{
  display:grid;
  place-items:center;
  
  width:560px; 
  height: 560px;
}